Scroll Compressors

While liquid cooling for oil-free and lubricated scroll compressor has been investigated in the past, patented liquid-cooled scroll technology from Air Squared offers the first oil-free scroll compressor design that provides effective cooling to both the fixed scroll and orbiting scroll. The patented technology allows coolant to be transferred between the fixed scroll and orbiting scroll without the use of dynamic seals.

Air-cooled scroll compressor designs are pressure-limited because the heat generated during compression causes the primary working components to thermally expand. The thermal expansion causes interference between the fixed scroll and orbiting scroll, eventually leading to mechanical failure. While the running clearance between the fixed scroll and orbiting scroll can be increased to avoid interference, this approach also decreases volumetric efficiency and pressure capability.

Liquid cooling allows for significantly more control over operating temperatures throughout the compression process. By removing heat generated during the compression process more effectively, thermal expansion is mitigated, allowing for high-pressure operation without sacrificing efficiency or reliability.

Sealed and Semi-hermetic configurations

Compared to air-cooled compressor designs, liquid cooling offers isolation of working fluid to ambient and drive componentry (i.e. motor). Air-cooled compressors cool the fixed scroll and orbiting scroll with ambient air. While this approach is adequate with an open-housing design, air colling is far less effective if the compression process is fully enclosed (e.g. sealed or semi-hermetic). Liquid-cooling solves this issue by providing effective cooling to the fixed scroll and orbiting scroll, even if the compressor is semi-hermetically sealed.

Liquid colling also operates independently of ambient conditions. This allows for effective cooling, even if the compressor is exposed to elevated ambient temperatures – as in under-the-hood vehicle applications.

For operation with flammable gases, such as O₂ and H₂, the “independent drive” series of liquid-cooled scroll compressors are easily configured with a magnetic coupling that fully isolates the working fluid from the motor.